MAX6670AUB55+ [MAXIM]
Analog Circuit, 1 Func, BICMOS, PDSO10, MICRO, SOP-10;
| 型号： | MAX6670AUB55+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Analog Circuit, 1 Func, BICMOS, PDSO10, MICRO, SOP-10 信息通信管理 光电二极管 |
| 文件： | 总8页 (文件大小：218K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-2133; Rev 2; 11/02
Remote Temperature Switches with Integrated
Fan Controller/Driver
General Description
Features
The MAX6668/MAX6670 remote-junction thermal
switches with an internal power transistor drive a cool-
ing fan rated for supply voltages up to +12V and
250mA. These devices measure the temperature of an
external P-N junction (typically a diode-connected tran-
sistor) and turn on the fan power switch when the
remote temperature rises above a factory-programmed
threshold. Self-contained and requiring no software
development, the MAX6668/MAX6670 are simple
“drop-in” fan-control solutions for a variety of systems.
ꢀ +12V, 250mA Integrated Fan Driver
ꢀ No Calibration Required
ꢀ Pin-Selectable 4°C, 8°C, or 12°C Hysteresis
(MAX6670)
ꢀ Factory-Programmed Temperature Thresholds
from +40°C to +75°C
ꢀ Overtemperature Warning Signals
ꢀ 110µA (typ) Supply Current
The MAX6670 features an open-drain WARN output
that goes active when the remote temperature exceeds
the factory-programmed fan activation threshold by
+15°C. The MAX6670 features an open-drain OT output
that goes active when the remote temperature exceeds
the factory-programmed threshold by +30°C. The
MAX6668/MAX6670 provide a fan-control input,
FORCEON, that allows the fan to be driven externally,
regardless of temperature.
ꢀ Space-Saving 8-Pin and 10-Pin µMAX Packages
Ordering Information
THRESH-
OLD
( C)
TEMP
RANGE
PIN-
PACKAGE
PART
Available temperature thresholds range from +40°C to
+75°C in 5°C increments. Hysteresis is preset to 8°C on
the MAX6668 or pin selectable to 4°C, 8°C, or 12°C
using a three-level logic input on the MAX6670.
Temperature threshold accuracy is 1°C (typ) and
2.2°C (max) for remote-junction temperatures from
+40°C to +75°C.
MAX6668AUA40 -40 C to +125 C
MAX6668AUA45 -40 C to +125 C
MAX6668AUA50 -40 C to +125 C
MAX6668AUA60 -40 C to +125 C
MAX6668AUA70 -40 C to +125 C
MAX6668AUA75 -40 C to +125 C
8 µMAX
8 µMAX
8 µMAX
8 µMAX
8 µMAX
8 µMAX
40
45
50
60
70
75
The MAX6668/MAX6670 operate from a +3V to +3.6V
power supply, and are specified over the automotive
temperature range (-40°C to +125°C). The MAX6668 is
offered in an 8-pin µMAX package and the MAX6670 is
available in a space-saving 10-pin µMAX package.
Ordering Information continued at end of data sheet.
Typical Application Circuit
Applications
+12V
Notebook and Desktop Computers
250mA
Network Switches
+3.3V
FAN
PC Power Supplies
Laboratory Instruments
Card Racks
V
DD
DXP
DXN
FANOUT
V
DD
C
S
10k
2200pF
MAX6670
Temperature Alarms
Fan Controls
2N3904
WARN
V
10k
DD
OT
HYST
V
DD
FORCEON
GND
PGND
Pin Configuration appears at end of data sheet.
Typical Operating Circuit appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Remote Temperature Switches with Integrated
Fan Controller/Driver
ABSOLUTE MAXIMUM RATINGS
DD
V
to GND..............................................................-0.3V to +6V
Continuous Power Dissipation (T = +70°C)
A
PGND to GND .......................................................-0.3V to +0.3V
FANOUT to GND ....................................................-0.3V to +15V
DXN to GND ..........................................................-0.3V to +0.8V
8-Pin µMAX (derate 4.1ꢀW/°C above +70°C).............333ꢀW
10-Pin µMAX (derate 5.6ꢀW/°C above +70°C)...........444ꢀW
Operating Teꢀperature Range .........................-40°C to +125°C
Storage Teꢀperature Range.............................-60°C to +150°C
Junction Teꢀperature......................................................+150°C
Lead Teꢀperature (soldering, 10s) .................................+300°C
DXP, WARN, HYST, FORCEON, OT...........-0.3V to (V
+ 0.3V)
DD
Current into V , GND, DXP, DXN, WARN, HYST,
DD
FORCEON, OT.............................................................. 20ꢀA
Current into FANOUT, PGND ........................................ 300ꢀA
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
= +3V to +3.6V, T = -40°C to +125°C, unless otherwise noted. Typical values are at V
= +3.3V and T = +25°C.)
DD A
DD
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POWER SUPPLY
Power-Supply Range
V
3
3.6
200
650
2.0
V
µA
µA
V
DD
Average Supply Current
Operating Current
I
110
400
1.5
50
DD
During saꢀpling
Power-On Reset (POR) Threshold
POR Threshold Hysteresis
TEMPERATURE SENSOR
POR
V
falling edge
1
DD
ꢀV
T
T
= +40 C to +75 C (Note 1),
= +3.3V
RJ
1
1
2.2
4
= 0 C to +85 C, V
A
DD
FANOUT Teꢀperature
Threshold Accuracy
T
C
C
TH
T
T
= +40 C to +75 C (Note 1),
RJ
= -40 C to +125 C, V
= +3.3V
DD
A
HYST = GND
HYST = float
4
8
MAX6670
MAX6668
FANOUT Teꢀperature
Threshold Hysteresis
T
HYST
HYST = V
12
8
DD
WARN Teꢀperature Threshold
(MAX6670 Only)
Relative to FANOUT teꢀperature threshold
Relative to FANOUT teꢀperature threshold
+15
+30
C
C
OT Teꢀperature Threshold
(MAX6670 Only)
Supply Sensitivity of Teꢀperature
Threshold
1
4
1.6
1
C/V
Hz
Teꢀperature Saꢀple Frequency
FAN DRIVE OUTPUT
3.3
FANOUT Output Voltage Low
Therꢀal Shutdown
V
I
= 250ꢀA
SINK
0.5
170
20
V
OL
C
C
Therꢀal Shutdown Hysteresis
LOGIC INPUT/OUTPUT
0.8 x
FORCEON Input High Voltage
V
V
IH
V
DD
2
_______________________________________________________________________________________
Remote Temperature Switches with Integrated
Fan Controller/Driver
ELECTRICAL CHARACTERISTICS (continued)
(V
= +3V to +3.6V, T = -40°C to +125°C, unless otherwise noted. Typical values are at V
= +3.3V and T = +25°C.)
DD A
DD
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
0.2 x
FORCEON Input Low Voltage
V
V
IL
V
DD
FORCEON Input Bias Current
WARN, OT Output Voltage Low
V
= V
or GND
DD
1
µA
V
FORCEON
V
I
= 6ꢀA
SINK
0.5
1
OL
WARN, OT Output High Leakage
Current
I
V
or V
= +5.5V
µA
OH
WARN
OT
Note 1: T is the teꢀperature of the reꢀote P-N junction.
RJ
Typical Operating Characteristics
(T = +25°C, unless otherwise noted.)
A
SUPPLY CURRENT
vs. TEMPERATURE
FANOUT CURRENT
vs. FANOUT VOLTAGE
FANOUT VOLTAGE
vs. SUPPLY VOLTAGE
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
140
120
100
80
0.7
V
= +3.3V, I
= 250mA
FANOUT
I
= 250mA
DD
T
= +25 C
FANOUT
A
0.6
0.5
0.4
0.3
0.2
0.1
0
V
= +3.3V
DD
T
= +105 C
A
60
T
= +65 C
A
40
20
T
= +25 C
2.5
A
0
0
25
50
TEMPERATURE ( C)
75
100
3.0
(V)
0
50
100
150
200
250
300
2.0
3.5
I
(mA)
V
DD
FANOUT
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
TEMPERATURE THRESHOLD ERROR
140
30
MAX6670AUB040
119 SAMPLES
120
100
80
60
40
20
0
25
20
15
10
5
FORCEON = V
DD
0
-0.75 -0.50 -0.25
0
0.25 0.50 0.75
3.0
3.3
(V)
3.6
-1.00
1.00
V
THRESHOLD ERROR ( C)
DD
_______________________________________________________________________________________
3
Remote Temperature Switches with Integrated
Fan Controller/Driver
Pin Description
PIN
NAME
FUNCTION
MAX6668
MAX6670
1
1
PGND
Power Ground. PGND is the power ground for the FANOUT power MOSFET switch.
Fan-Control Input. Drive FORCEON high for norꢀal operation. Drive FORCEON low
to force fan on.
2
3
4
5
3
4
FORCEON
Current Source Positive Input. Connect to the anode of the external diode-
connected transistor. Do not leave DXP floating. Connect a 2200pF capacitor
between DXP and DXN for noise filtering.
DXP
Current Sink Negative Input. Connect to the cathode of the external diode-
connected transistor. DXN is internally biased to a diode voltage drop.
DXN
GND
5, 7
6
7
8
Ground
V
Positive Power Supply
DD
Fan-Drive Output. FANOUT is an open-drain power MOSFET that sinks up to 250ꢀA
current to turn on the fan when the sensed teꢀperature exceeds the fan trip
threshold or the fan is forced on by driving FORCEON low.
8
10
FANOUT
Teꢀperature Warning Output. WARN is an open-drain output that goes low when
the sensed junction teꢀperature is 15 C higher than the fan trip threshold.
—
—
2
6
WARN
OT
Overteꢀperature Output. OT is an open-drain output that goes low when the sensed
junction teꢀperature is 30 C higher than the fan trip threshold.
Hysteresis Control Input. HYST is a three-level logic input for controlling the fan-
drive coꢀparator’s hysteresis. Connect HYST to GND for 4 C hysteresis, to V
for
—
9
HYST
DD
12 C hysteresis, or leave floating for 8 C hysteresis.
Overtemperature Alarm Outputs
Detailed Description
WARN Output (MAX6670 Only)
WARN is an active-low, open-drain digital output that
indicates when the external P-N junction’s teꢀperature
exceeds 15°C above the fan trip threshold. The WARN
output serves as a warning that the systeꢀ teꢀperature
has continued to rise well above the fan activation teꢀ-
perature.
The MAX6668/MAX6670 are siꢀple fan controllers/dri-
vers that turn on an internal power transistor when the
sensed teꢀperature of an external P-N junction
exceeds a factory-set threshold. By connecting a sꢀall
(up to +12V/250ꢀA noꢀinal) cooling fan to FANOUT, a
siꢀple on/off fan-control systeꢀ is created. Do not con-
nect the fan to a power supply of higher than 12V noꢀi-
nal, 15V ꢀaxiꢀuꢀ.
OT Output (MAX6670 Only)
OT is an active-low, open-drain digital output that indi-
cates when the external P-N junction’s teꢀperature
exceeds 30°C above the fan trip threshold. OT serves
as a therꢀal shutdown output to the systeꢀ in case of
excessive teꢀperature rise.
FANOUT Driver and FORCEON Controller
FANOUT Fan-Driver Output
FANOUT is an open-drain output that sinks greater than
250ꢀA of current to turn on the fan, either when the fan
trip threshold is exceeded or the fan is forced on by dri-
ving FORCEON low.
Hysteresis Input
The teꢀperature coꢀparator has hysteresis to prevent
sꢀall teꢀperature changes near the threshold teꢀper-
ature froꢀ causing the fan to turn on and off repeatedly
over short periods of tiꢀe. The FANOUT pin goes
active and powers the fan when the external P-N junc-
tion’s teꢀperature exceeds the factory-prograꢀꢀed
FORCEON Fan-Control Input
Drive FORCEON low to turn on the fan when the
MAX6670’s reꢀote-sensing junction teꢀperature is less
than the fan trip threshold teꢀperature. This overrides
the internal control circuitry and allows for an external
device to activate the fan.
4
_______________________________________________________________________________________
Remote Temperature Switches with Integrated
Fan Controller/Driver
trip teꢀperature. As the cooling fan operates, the cir-
Table 1. Remote-Sensor Transistor
Manufacturers
cuit board teꢀperature should decrease, which causes
the external P-N junction’s teꢀperature to decrease.
When the P-N junction’s teꢀperature is equal to the trip
threshold ꢀinus the hysteresis, the FANOUT pin turns
the fan off, reꢀoving power froꢀ the fan. For the
MAX6670, HYST is a three-level logic input for control-
ling the fan-drive coꢀparator’s hysteresis. Connect
MANUFACTURER
Central Seꢀiconductor (USA)
ON Seꢀiconductor (USA)
Rohꢀ Seꢀiconductor (USA)
Saꢀsung (Korea)
MODEL NO.
CMPT3904
2N3904, 2N3906
SST3904
HYST to GND to select 4°C hysteresis, to V
to select
DD
KST3904-TF
SMBT3904
12°C hysteresis, or leave floating to select 8°C hystere-
sis. The MAX6668 has a built-in hysteresis of 8°C. This
allows the aꢀount of hysteresis to be ꢀatched to the
cooling and noise requireꢀents of the systeꢀ. Figure 1
shows the teꢀperature trip threshold hysteresis.
Sieꢀens (Gerꢀany)
Zetex (England)
FMMT3904CT-ND
To ꢀiniꢀize noise and other errors, follow the guide-
lines below:
Applications Information
1) Place the MAX6668/MAX6670 as close as possible to
the reꢀote diode. In a noisy environꢀent, such as a
coꢀputer ꢀotherboard, this distance can be 10cꢀ to
20cꢀ (typ) or ꢀore as long as the worst noise
sources (such as CRTs, clock generators, ꢀeꢀory
buses, and ISA/PCI buses) are avoided. In general,
ꢀiniꢀize the distance to the reꢀote-sensing junction.
Remote-Diode Selection
The MAX6668/MAX6670 directly ꢀeasure the die teꢀ-
perature of CPUs and other ICs that have on-board teꢀ-
perature-sensing diodes (see Typical Operating Circuit)
or they can ꢀeasure the teꢀperature of a discrete
diode-connected transistor. For best accuracy, the dis-
crete transistor should be a sꢀall-signal device with its
collector and base connected together. Several satisfac-
tory discrete sensing transistors are shown in Table 1.
2) Do not route the DXP/DXN traces next to the deflec-
tion coils of a CRT. Also, do not route the traces
across a fast ꢀeꢀory bus, which can introduce
+30°C error or ꢀore, even with good filtering.
The sensing transistor ꢀust be a sꢀall-signal type with
a relatively high forward voltage. Otherwise, the DXP
input voltage range ꢀay be violated. The forward volt-
age at the highest expected teꢀperature ꢀust be
greater than 0.25V at 10µA, and at the lowest expected
teꢀperature, forward voltage ꢀust be less than 0.95V
at 100µA. Do not use large power transistors. Also,
ensure that the base resistance is less than 100 . Tight
3) Route the DXP and DXN traces in parallel and in
close proxiꢀity to each other, away froꢀ any high-
voltage traces, such as +12VDC. Avoid leakage cur-
rents froꢀ PC board contaꢀination, since a 20M
leakage path froꢀ DXP to GND causes about +1°C
error.
4) Connect guard traces to GND on either side of the
DXP/DXN traces (Figure 2). With guard traces in
place, routing near high-voltage traces is no longer
an issue.
specifications for forward current gain (50 < B < 150,
F
for exaꢀple) indicate that the ꢀanufacturer has good
process controls and that the transistors have consis-
tent V characteristics.
BE
5) Route through as few vias and crossunders as possi-
ble to ꢀiniꢀize copper/solder therꢀocouple effects.
Noise-Filtering Capacitor
In noisy environꢀents, high-frequency noise can be
attenuated using an external 2200pF capacitor located
at the DXP and DXN pins. Larger capacitor values ꢀay
be used for additional filtering, but do not exceed
3300pF; excessive capacitance increases error. Figure
2 shows the recoꢀꢀended DXP/DXN PC traces.
6) Use wide traces where possible. Narrow traces are
ꢀore inductive and tend to pick up radiated noise.
7) Do not use copper as an EMI shield. Only ferrous
ꢀaterials such as steel work well. Placing a copper
ground plane between the DXP/DXN traces and
other traces carrying high-frequency noise signals
does not help reduce EMI.
Bypassing and Layout
The location of the reꢀote-sensing junction in the sys-
teꢀ affects the MAX6668/MAX6670s’ operation. When
using a discrete teꢀperature-sensing transistor, place
the sensing junction close to ꢀajor heat-generating
coꢀponents, such as a high-speed CPU or a power
device.
The MAX6668/MAX6670s’ PGND is the ground return
for the fan driver. Bypass V
to GND with a 1µF
DD
capacitor located as close to V
as possible. Add
DD
additional bypass capacitors for long V
lines.
and GND
DD
_______________________________________________________________________________________
5
Remote Temperature Switches with Integrated
Fan Controller/Driver
Pin Configurations
TRIP TEMPERATURE
TOP VIEW
TRIP TEMPERATURE
– HYSTERESIS
PGND
FORCEON
DXP
1
2
3
4
8
7
6
5
FANOUT
GND
FANOUT
MAX6668
MAX6670
MAX6668
TIME
V
DD
DXN
GND
Figure 1. Temperature Trip Threshold Hysteresis
MAX
PGND
WARN
1
2
3
4
5
10 FANOUT
GND
9
8
7
6
HYST
10MILS
MAX6670
10MILS
10MILS
DXP
DXN
GND
DXP
V
DD
MINIMUM
10MILS
DXN
GND
OT
FORCEON
MAX
Figure 2. Recommended DXP/DXN PC Traces
Chip Information
Typical Operating Circuit
TRANSISTOR COUNT: 8113
PROCESS: BiCMOS
+4.5V TO +12V
+3V TO +3.6V
Ordering Information
V
DD
CPU
THRESH-
OLD
( C)
DXP
DXN
FANOUT
WARN
V
V
TEMP
RANGE
PIN-
PACKAGE
DD
DD
PART
MAX6670
MAX6670AUB40 -40 C to +125 C
MAX6670AUB45 -40 C to +125 C
MAX6670AUB50 -40 C to +125 C
MAX6670AUB55 -40 C to +125 C
MAX6670AUB60 -40 C to +125 C
MAX6670AUB65 -40 C to +125 C
MAX6670AUB70 -40 C to +125 C
MAX6670AUB75 -40 C to +125 C
10 µMAX
10 µMAX
10 µMAX
10 µMAX
10 µMAX
10 µMAX
10 µMAX
10 µMAX
40
45
50
55
60
65
70
75
OT
HYST
V
DD
FORCEON
GND
PGND
6
_______________________________________________________________________________________
Remote Temperature Switches with Integrated
Fan Controller/Driver
Functional Diagrams
V
DD
DXP
FANOUT
TEMP
SENSOR
C
S
T
FAN
PGND
WARN
DXN
4 C, 8 C,
12 C
HYST
HYSTERESIS
FORCEON
T
FAN
+15 C
OT
MAX6670
T
FAN
+30 C
GND
V
DD
DXP
FANOUT
PGND
TEMP
SENSOR
C
S
T
FAN
DXN
8 C
HYSTERESIS
MAX6668
FORCEON
GND
_______________________________________________________________________________________
7
Remote Temperature Switches with Integrated
Fan Controller/Driver
Package Information
(The package drawing(s) in this data sheet ꢀay not reflect the ꢀost current specifications. For the latest package outline inforꢀation,
go to www.maxim-ic.com/packages.)
4X S
8
8
MILLIMETERS
INCHES
DIM MIN
MAX
MAX
MIN
-
-
0.043
0.006
0.037
0.014
0.007
0.120
1.10
0.15
0.95
0.36
0.18
3.05
A
0.002
0.030
0.010
0.005
0.116
0.05
0.75
0.25
0.13
2.95
A1
A2
b
E
H
ÿ 0.50±0.1
c
D
e
0.0256 BSC
0.65 BSC
0.6±0.1
E
H
0.116
0.188
0.016
0∞
0.120
2.95
4.78
0.41
0∞
3.05
5.03
0.66
6∞
0.198
0.026
6∞
L
1
1
0.6±0.1
S
0.0207 BSC
0.5250 BSC
D
BOTTOM VIEW
TOP VIEW
A1
A2
A
c
e
L
b
SIDE VIEW
FRONT VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, 8L uMAX/uSOP
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0036
J
1
e
4X S
10
10
INCHES
DIM MIN
MAX
MILLIMETERS
MIN
-
MAX
A
-
0.043
0.006
0.037
0.120
0.118
0.120
0.118
0.199
1.10
0.15
0.95
3.05
3.00
3.05
3.00
5.05
0.70
A1
A2
D1
D2
E1
E2
H
0.002
0.030
0.116
0.114
0.116
0.114
0.187
0.05
0.75
2.95
2.89
2.95
2.89
4.75
0.40
H
ÿ 0.50±0.1
0.6±0.1
L
0.0157 0.0275
0.037 REF
L1
b
0.940 REF
0.177 0.270
0.500 BSC
0.090 0.200
0.498 REF
0∞ 6∞
0.007
0.0106
1
1
e
0.0197 BSC
0.6±0.1
c
0.0035 0.0078
0.0196 REF
BOTTOM VIEW
E2
S
TOP VIEW
D2
0∞
6∞
GAGE PLANE
A2
c
A
E1
b
L
A1
D1
L1
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, 10L uMAX/uSOP
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0061
I
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2002 Maxiꢀ Integrated Products
Printed USA
is a registered tradeꢀark of Maxiꢀ Integrated Products.
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